AQUACULTURE
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2013
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IF 2.009
Shi-wei Xie,Li-xia Tian,Yan Jin,Hui-jun Yang,Gui-ying Liang,Yong-jian Liu
An 8-week feeding trial was conducted to evaluate the optimum dietary glycine level in low fishmeal diet for juvenile Pacific white shrimp , Litopenaeus vannamei . Six practical diets (44.4% protein, 8.8% lipid) were formulated to contain graded levels (2.26, 2.33, 2.44, 2.58, 2.67 and 2.74%) of l -glycine. Each diet was randomly assigned to triplicate groups of 30 shrimps (approximately 0.61 g) and the shrimps were fed 4 times a day to apparent satiation. The results indicated that the weight gain and specific growth rate were significantly increased with the supplementation of glycine. The highest weight gain and specific growth rate were observed at 2.56% dietary glycine, and then decrease with a further increase in dietary glycine. Hepatosomatic index , protein productive value and condition factor were also significantly influenced by the dietary glycine levels and show a similar trend to those of growth performance. There were no significant differences observed in feed efficiency , protein efficiency ratio and survival among all treatments. Mg, Ca and Fe concentrations in whole body were significantly increased with the supplementation of glycine. Non-essential amino acid, essential amino acid and arginine ratio in muscle were significantly affected by the dietary glycine levels. Dietary glycine levels higher than 2.44% significantly increased the survival of shrimps after 2 h and 3 h of acute salinity change, and T-SOD activity and Na + /K + -ATPase activity in hematological and hepatopancreas before and after acute salinity change are also significantly affected by the dietary glycine levels. Analysis by second-order regression of weight gain indicated that the optimal dietary glycine level was 2.54% of the dry diet (5.7% of the dietary protein and 6.66% of the dietary amino acids).
研究领域:
水产养殖
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营养学
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海洋生物学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Tong Wang,Dan Li,Xin Tian,Guolin Huang,Meilin He,Changhai Wang,Ali Nawaz Kumbhar,Abeselom Ghirmai Woldemicael
Salinity stress in estuarine environments poses a significant challenge for microalgal survival and proliferation. The interaction between microalgae and bacteria shows promise in alleviating the detrimental impacts of salinity stress on microalgae. Our study investigates this interaction by co-cultivating Chlorella sorokiniana , a freshwater microalga, with a marine growth-promoting bacterium Pseudomonas gessardii , both of which were isolated from estuary. In this study, bacteria were encapsulated using sodium alginate microspheres to establish an isolated co-culture system, preventing direct exposure between microalgae and bacteria. We evaluated microalgal responses to different salinities (5 PSU, 15 PSU) and interaction modes (free-living, gel-encapsulated), focusing on growth, photosynthesis, cellular metabolism, and extracellular polymeric substances (EPS) properties. High salinity inhibited microalgal proliferation, while gel-fixed interaction boosted Chlorella growth rate by 50.7 %. Both attached and free-living bacteria restored Chlorella 's NPQ to normal levels under salt stress. Microalgae in the free-living interaction group exhibited a significantly lower respiratory rate compared to the pure algae group (−17.2 %). Increased salinity led to enhanced EPS polysaccharide secretion by microalgae, particularly in interaction groups (19.7 %). Both salt stress and interaction increased the proportion of aromatic proteins in microalgae's EPS, enhancing its stability by modulating EPS glycosidic bond C-O-C and protein vibrations. This alteration caused microalgal cells to aggregate, free-living bacteria co-culture group, and fixed co-culture group increasing by 427.5 %, 567.1 %, and 704.1 %, respectively. In gel-fixed bacteria groups, reduced neutral lipids don't accumulate starch instead, carbon redirects to cellular growth, aiding salt stress mitigation. These synergistic activities between salinity and bacterial interactions are vital in mitigating salinity stress, improving the resilience and growth of microalgae in saline conditions. Our research sheds light on the mechanisms of microalgal-bacterial interactions in coping with salt stress, offering insights into the response of estuarine microorganisms to global environmental changes and their ecological stability.
研究领域:
微生物学
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环境科学
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海洋生物学
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植物生理学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Water
·
2025
·Vol. 17
·期 17
·2611
·
IF 3
Keying Sun,Huining Zhang,Kefeng Zhang,Jianqing Ma,Zhengmin Pan,Shuting Zhang
The anaerobic ammonium oxidation (anammox) process offers potential for saline wastewater treatment but is hindered by salt inhibition. This study investigates the salt tolerance mechanisms of granular (R1), biofilm-carrier (R2), and floccular (R3) sludge in up-flow anaerobic sludge blanket (UASB) reactors under 0–20 g/L NaCl. Granular sludge outperformed other biomass types, maintaining >90% ammonia nitrogen (NH4+-N) removal at 20 g/L NaCl due to structural stability and extracellular polymeric substances (EPS) adaptation (shift from hydrophobic proteins to polysaccharides). Microbial analysis revealed a transition fromPlanctomycetes/Proteobacteriato salt-tolerantPseudomonadota, withCandidatus_KueneniareplacingCandidatus_Brocadiaas the dominant anaerobic ammonium oxidation bacteria (AnAOB) (reaching 14.5% abundance in R1). Genetic profiling demonstrated coordinated nitrogen metabolism: Hzs/Hdh inhibition (>85%) and NirBD/NrfAH activation (0.23%) elevatedNH4+-N, while NarGIV/NapA decline (1.10%→0.58%) increased nitrate nitrogen (NO3−-N). NxrB/NirSK maintained low nitrite nitrogen (NO2−-N), and GltBD upregulation (0.43%) enhanced osmoregulation. These findings underscore the superior resilience of granular sludge under high salinity, linked to microbial community shifts and metabolic adaptations. This study provides critical insights for optimizing anammox processes in saline environments, emphasizing the importance of biomass morphology and microbial ecology in mitigating salt inhibition.
研究领域:
环境工程
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微生物生态学
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废水处理
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生物技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）